Bull Run River (Oregon) - Watershed

Watershed

The Bull Run watershed drains 139 square miles (360 km2), most of which is in the Mount Hood National Forest in Multnomah and Clackamas counties in northwest Oregon. The confluence of the Bull Run and Sandy rivers at Dodge Park, about 20 miles (32 km) east of downtown Portland, marks the watershed's western (downstream) end, while on the east it borders Hood River County, and at Hiyo Mountain it is about 6 miles (9.7 km) northwest of Mount Hood in the Cascade Range. It is a sub-watershed of the Lower Columbia–Sandy Watershed. Elevations within the watershed range from 4,750 feet (1,450 m) at Buck Peak on the watershed’s northeastern boundary to 243 feet (74 m) at the mouth of the Bull Run River.

As the main source of Portland's drinking water, the watershed is largely restricted to uses related to water collection, storage, and treatment, and to forest management. The city's drinking-water protection area consists of the 102 square miles (260 km2) of the basin upstream of the water-supply intake at RM 6.2 (RK 10). The protection area is part of a larger restricted zone, the BRWMU, which covers 143 square miles (370 km2). It lies mostly within Multnomah and Clackamas counties but extends in places along its eastern edge into Hood River County. As of 2010, the Forest Service manages 95 percent of the BRWMU on land owned by the federal government; the Portland Water Bureau manages the 4 percent that is owned by the City of Portland, and the Bureau of Land Management manages the remaining 1 percent, which is on federal land. Small portions of the watershed along the lower main stem or along tributaries that are partly outside the BRWMU and that enter the main stem below the drinking-water intake are owned by the City of Portland or other local governments or are privately owned.

Watersheds bordering the Bull Run River drainage basin are those of the West Fork Hood River to the east and northeast, the Sandy River to the south and west, and the Columbia River to the north. Small Columbia River tributaries, each with a subwatershed bordering the Bull Run watershed, flow north from a ridge between the Bull Run and Columbia rivers. These include Eagle, Tanner, Moffett, McCord, Horsetail, Oneonta, Multnomah, and Bridle Veil creeks, which plunge over one or more waterfalls as they enter the Columbia Gorge.